Great Bustard
A species of Great Bustard Scientific name : Otis tarda Genus : Great Bustard
Great Bustard, A species of Great Bustard
Botanical name: Otis tarda
Genus: Great Bustard
Photo By Andrej Chudý , used under CC-BY-SA-2.0 /Cropped and compressed from original
Description
The adult male great bustard is amongst the heaviest living flying animals. A male is typically 90–105 cm (2 ft 11 in–3 ft 5 in) tall, with a length of around 115 cm (3 ft 9 in) and has a 2.1–2.7 m (6 ft 11 in–8 ft 10 in) wingspan. The male can range in weight from 5.8 to 18 kg (13 to 40 lb). The heaviest verified specimen, collected in Manchuria, was about 21 kg (46 lb), a world record for heaviest flying bird. In a study in Spain, one male weighed as much as 19 kg (42 lb). Larger specimens have been reported but remain unverified. Average male weights as reported have been fairly variable: in Russia, males weighed a median of 9.2 kg (20 lb); in Spain, males weighed a mean of 9.82 kg (21.6 lb) during breeding season and 10.62 kg (23.4 lb) during non-breeding; in Germany, males weighed a mean of 11.97 kg (26.4 lb); and the Guinness World Records has indicated that prior to their extirpation male bustards in Great Britain weighed an average of 13.5 kg (30 lb). Average weight of males is almost an exact match to that of male Kori bustards. Among all flying animals and land birds, male Andean condors (Vultur gryphus) may match or exceed the mean body masses of these male bustards but not their maximum weights. Furthermore, male swans of the two largest species (trumpeter and mute) may attain a similar average mass depending on season and region. Among both bustards and all living birds, the upper reported mass of this species is rivaled by that of the kori bustard (Ardeotis kori), which, due to its relatively longer tarsi and tail, is both longer and taller on average and is less sexually dimorphic. In terms of weight ranges reported, the great Indian bustard (Ardeotis nigriceps) also only lags slightly behind these species. The great bustard is also arguably the most sexual dimorphic extant bird species, in terms of the size difference between males and females. Adult male great bustards measured in Spain weighed on average 2.48 times more than females. Going on mass, the only known bird with a higher dimorphism is the green peafowl (Pavo muticus) as the males are apparently near four times as heavy as females. The female is about a third smaller in linear dimensions, typically measuring 75 to 85 cm (2 ft 6 in to 2 ft 9 in) in height, about 90 cm (2 ft 11 in) in length and 180 cm (5 ft 11 in) across the wings. Overall, the female's weight can range from 3.1 to 8 kg (6.8 to 17.6 lb). Like male weights, females weights are quite variable as reported: in Germany, females had a mean weight of 3.82 kg (8.4 lb), in Spain, females had a mean weight of 4.35 kg (9.6 lb) and in Russia, females reportedly had a median weight of 6 kg (13 lb). The latter figure indicates that eastern birds (presumably O. t. dybowskii) are considerably less sexually dimorphic in body mass than in other populations. Perhaps because of this physical sexual dimorphism, there is a skewed sex ratio of about 1.5:1 female to male. An adult male is brown above, barred with blackish colouration, and white below, with a long grey neck and head. His breast and lower neck sides are chestnut and there is a golden wash to the back and the extent of these bright colours tending to increase as the male ages. In the breeding season, the male has long white neck bristles, which measure up to 12–15 cm (4.7–5.9 in) in length, continually growing from the third to the sixth year of life. In flight, the long wings are predominantly white with brown showing along the edges of the lower primary and secondary feathers and a dark brown streak along the upper-edge of the wing. The breast and neck of the female are buff, with brown and pale colouration over the rest of the plumage rendering it well camouflaged in open habitats. Immature birds resemble the female. The eastern subspecies (O. t. dybowskii) is more extensively grey in colour in both sexes, with more extensive barring on the back. The great bustard has long legs, a long neck and a heavy, barrel-chested body. It is fairly typical of the family in its overall shape and habitat preferences. Three other bustard species overlap in range with this species: the Macqueen's (Chlamydotis macqueenii), houbara (Chlamydotis undulata) and little bustards (Tetrax tetrax). However, none of these attains the plumage coloration nor approach the body sizes of this species. Thus, the great bustard is essentially unmistakable.
Size
75 - 105 cm
Colors
Brown
Black
Bronze
Gray
White
Life Expectancy
10-28 years
Feeding Habits
Great Bustard are omnivorous, seasonally varying their diet, primarily consuming green plants, invertebrates, and seeds. They favor legumes, crucifers, and grains like wheat and barley. Great Bustard predominantly forage on insects in summer, especially as juveniles, but switch to plants by winter. Occasional small vertebrates supplement their diet, and they uniquely ingest toxic beetles for presumed self-medication.
Habitat
Great Bustard typically inhabits spacious grasslands, steppes, and agricultural regions without dense tree cover. These landscapes include open fields, pastures, and fallow land with a varied low-intensity land-use pattern, which is essential for their year-round requirements. Insect- and flower-rich areas are key during spring and summer, while stubble fields are preferred post-breeding, and lucerne fields provide sustenance in winter. Regional preferences may see great Bustard utilizing dehesas and olive groves in southwestern Iberia seasonally. Habitat selection is influenced by availability and varies by season and sex; males often favor fallow fields during breeding, while females may choose cereal fields. Conservation efforts suggest that a rotational crop system incorporating cereals and fallows could benefit great Bustard's diverse habitat needs.
Dite type
Herbivorous
People often ask
Migration Overview
Some individuals in Iberian populations make short seasonal movements of 5 – 200 km, particularly males which appear to be move in response to higher summer temperatures. European populations are sedentary or make irregular movements in response to severe winter weather. Populations breeding along the Volga River in Russia migrate 1000 km to overwinter in Crimea and Kherson Oblast. Populations breeding in northern Mongolia migrate over 2000 km to overwinter in Shaanxi Province of China. In migratory populations, great bustards often gather in larger numbers at pre-migratory sites in order to move collectively to winter grounds. In the Iberian Peninsula, bustards that engage in migration seem to choose different periods for movements based on sex. No population is known to use the same grounds for wintering and summering. Great Bustards are strong fliers and reach speeds of 48 km/hr to 98 km/hr during migration.
General Info
Behavior
The species is gregarious, especially in winter when gatherings of several dozen birds may occur. Male and female groups do not mix outside of the breeding season. The great bustard has a stately slow walk but tends to run when disturbed rather than fly. Running speeds have not been measured but adult females have been known to outrun red foxes (Vulpes vulpes), which can reach a trotting speed of 48 km/h (30 mph). However, they can be fairly strong fliers as well, especially during seasonal movements, and can reach speeds of up to 80 km/h (50 mph) in flight. Both sexes are usually silent but can engage in deep grunts when alarmed or angered. The displaying adult male may produce some booming, grunting and raucous noises. The female may utter some guttural calls at the nest and brooded young make a soft, trilling call in communication with their mothers. The Asian and Russian populations of the species are migratory and will gather in large numbers at pre-migratory sites in order to move collectively to winter grounds. In the remainder of the range, such as Central Asia, only partial migrations may occur based on seasonal food availability. In the Iberian Peninsula, bustards that engage in migration seem to choose different periods for movements based on sex. No population is known to use the same grounds for wintering and summering.
Distribution Area
As of 2008, the global population numbered between 44,000 to 51,000 birds (Palacin & Alonso 2008), about 38,000 to 47,000 in Europe, with 30,000 or more than half in Spain. Hungary had the next largest Great Bustard population with about 1,555 in the year 2012, followed by Ukraine and Austria. Between 4,200 and 4,500 were found in east Asia. In recent times, there have been steep declines throughout eastern and central Europe and in Asia, particularly in Kazakhstan and Mongolia. Sizeable populations exist in Spain (23,055 birds), Russia (8,000 birds), Turkey (800–3,000 birds), Portugal (1,435 birds) and Mongolia (1,000 birds). In Germany and Austria the populations are small (Germany 2016: 232 birds; Austria 2012: 335 birds) but steadily growing for about two decades. Elsewhere, the populations are declining due to habitat loss throughout its range. A sizeable population also exists in Hungary (1,100–1,300 birds) where the Eastern European steppe zone ends, near Dévaványa town and also in the Hortobágy National Park, Nagykunság and Nagy-Sárrét regions. The population is down from a population of 10,000–12,000 before the Second World War. Agrienvironment schemes as unirrigated legumes fostered a population increase of great bustards in Castilla y Leon, central Spain.
Species Status
The great bustard is classified as vulnerable at the species level. There are myriad threats faced by great bustards. Increasing human disturbance could lead to habitat loss caused by the ploughing of grasslands, intensive agriculture, afforestation, increased development of irrigation schemes, and the construction of roads, power lines, fencing and ditches. Mechanisation, chemical fertilizers and pesticides, fire and predation by dogs are serious threats for chicks and juveniles, and hunting of adults contributes to high mortality in some of their range countries. Agricultural activity is a major disturbance at nest and, in Hungary, few successful nests are found outside of protected areas. Bustards, despite their large size, are able to fly at high speed and are often mutilated or killed by overhead electricity cables, which are placed in the West Pannonia region of Eastern Austria and Western Hungary just at their flying height. The electricity companies affected have buried part of the dangerous cables, and have marked remaining aerial parts with fluorescent markers to warn off the birds. These measures have rapidly reduced bustard mortality. Bustards are also occasionally killed by collisions with automobiles or by entanglement in wires. The great bustard was formerly native in Great Britain and a bustard forms part of the design of the Wiltshire Coat of Arms and as supporters for the Cambridgeshire arms. As early as 1797, the naturalist and wood engraver Thomas Bewick commented in his A History of British Birds that "Both this [the little bustard] and the Great Bustard are excellent eating, and would well repay the trouble of domestication; indeed, it seems surprising, that we should suffer these fine birds to be in danger of total extinction, although, if properly cultivated, they might afford as excellent a repast as our own domestic poultry, or even as the Turkey, for which we are indebted to distant countries." Bewick's prediction was correct; the great bustard was hunted out of existence in Britain by the 1840s. In 2004, a project overseeing the reintroduction to Salisbury Plain in Wiltshire using eggs taken from Saratov in Russia was undertaken by The Great Bustard Group, a UK Registered Charity that aims to establish a self-sustaining population of great bustards in the UK. The reintroduced birds have laid eggs and raised chicks in Britain in 2009 and 2010. Although the great bustard was once native to Britain, great bustards are considered an alien species under English law. The reintroduction of the great bustard to the UK by the Great Bustard Group is being carried out in parallel with researchers from the University of Bath who are providing insight into the habitat of native great bustard populations in Russia and Hungary. On January 19, 2011, it was announced that the Great Bustard Project had been awarded EU LIFE+ funding, reportedly to the tune of £1.8 million. In Hungary, where the species is the national bird, great bustards are actively protected. The Hungarian authorities are seeking to preserve the long-term future of the population by active protection measures; the area affected by the special ecological treatment had grown to 15 km (5.8 sq mi) by the summer of 2006. Under the auspices of the Convention on Migratory Species of Wild Animals (CMS), also known as the Bonn Convention, the Memorandum of Understanding (MoU) on the Conservation and Management of Middle-European Populations of the Great Bustard was concluded and came into effect on June 1, 2001. The MoU provides a framework for governments, scientists, conservation bodies and others to monitor and coordinate conservation efforts in order to protect the middle-European populations of the great bustard.
Photo By Andrej Chudý , used under CC-BY-SA-2.0 /Cropped and compressed from original
Scientific Classification
Phylum
Chordates Class
Birds Order
Bustards Family
Bustards Genus
Great Bustard Species
Great Bustard